The present invention relates to a pattern plate carrier for air-pressurized compaction processes and, more particularly, a carrier for supporting a pattern plate in a sand mold making process wherein the carrier is equipped with air venting structure running along the inner contour of the molding box of the sand molding apparatus.
In modern sand molding processes used to produce sand molds for casting molten metal, compressed air is made to flow vertically from the top of the sand located in the sand mold to the bottom. In order to obtain better compaction of the sand on the pattern in the molding apparatus, particularly in the marginal zones along the interior wall of the molding box, the compressed air flowing in on the upper side of the molding box and vertically down through the molding sand must be able to escape on the pattern side of the molding box. Heretofore, this has been accomplished by providing orifices in the pattern plate in the form of round nozzles in the area of the pattern plate between the pattern and the molding box, see for example German Patentschrift 26 08 740. As a result of the foregoing, the area of the pattern plate which can be utilized is greatly reduced.
Naturally, it would be highly desirable to provide a sand molding apparatus which would allow for the air flowing through the sand material to escape on the pattern side of the mold while at the same time allowing for high utilization of the area of the pattern plate thereby resulting in higher casting yield per mold box.
Accordingly, it is the principal object of the present invention to provide an apparatus as aforesaid which allows for an enlarging of the pattern plate area utilized in a molding box thereby resulting in higher casting yield per molding box.
It is a further object of the present invention to provide a pattern plate carrier with venting structure for allowing air to escape the molding space on the pattern side of the molding box.
It is a particular object of the present invention to provide a pattern plate carrier as aforesaid which includes elongated slotted bars around the periphery of the pattern plate for venting air.
It is a still further object of the present invention to provide a pattern plate carrier which is simple in structure and efficient in operation.
Further objects and advantages of the present invention will appear hereinbelow.